Fuel Cell Cars Explained

Unfamiliar technologies are easy to misunderstand, and the fuel cell vehicle could be a poster child for both the unfamiliar and the misunderstood.

But the truth is that while the technology behind making a fuel cell system to power an automobile is complicated, fuel cells have been around for almost 175 years.

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The short definition of a fuel cell vehicle is that it is a type of hybrid electric car that uses an on-board thermo-chemical device to produce electricity from hydrogen and oxygen and uses that electricity to power the electric motor.

It can be a complicated process.

Instead of a battery-electric vehicle’s bulky, heavy and expensive battery pack that’s recharged from the power grid over a period of several hours, a fuel-cell electric car (FCEV) uses compressed hydrogen gas as its energy carrier. It is stored on the car in high-strength cylindrical tanks.

The fuel cell, an expensive but compact component, draws in the hydrogen along with oxygen from the ambient air, passes the hydrogen through a catalyst (usually platinum) that extracts the electrons, producing electricity as they interact with the oxygen. The hydrogen then combines with oxygen to form H20 – water.

Heat from the reaction inside the fuel cell vaporizes the water, so the only tailpipe emission is a trickle of steam. The electricity “generated” in the fuel cell is used to power the vehicle’s electric drive motor.

From that point on there’s little difference between a fuel cell car’s operation and the operation of a battery-electric vehicle.

The upside of a fuel cell vehicle is that its hydrogen storage tanks can be refilled in about 5 minutes, and can carry sufficient hydrogen to deliver 300 miles or range, making it competitive with gasoline and diesel vehicles in terms of range.

FCEVs also are much cleaner than petroleum-fueled vehicles, with no harmful tailpipe emissions and lower overall emissions than produced in the extraction, refining and use of petroleum fuels.

But fuel-cell electric vehicles typically are not as clean on a so-called power plant-to-wheels basis as battery electric cars, in part because they are not as efficient in converting energy to usable power.

They also are fairly expensive because the fuel cell components are not yet in mass production, so there is no economy of scale.

Additionally, while efforts are being made to increase the number of hydrogen fuel stations, there are only a few dozen in operation nationally, almost all of them in California. That has limited early sales of FCEVs to the Southern California and San Francisco Bay areas and the island of Oahu in Hawaii. At present the only commercially available FCEVs are the fuel-cell Nexo crossover made by Hyundai; a small Toyota sedan, the Mirai; and the midsize Honda Clarity FCEV sedan.

Several other automakers have experimental FCEVs on the road in the U.S., Western Europe and Asia. More than a dozen fuel-cell electric cars are expected to be in the retail market globally by 2025. (Article updated 10/10/19.)